The invention involves a device for the filtration of pourable media using porous, ceramic rods. Devices of this type are used in numerous industry branches, for example, in the food industry or in the pharmaceutical industry.
Such a membrane module has become known, for example, from the patent EP 0 270 051. EP 0 748 250 B1 describes a membrane module in which the annular gap between the individual ceramic rod and the sheath surrounding it is completely filled by permeate, and thus free of any solids.
EP 0 333 753 B1, on the other hand, describes a device in which the collecting chamber surrounding the ceramic rod is filled from a large quantity of small filling bodies, which should make it so that the motive pressure over the length of the ceramic rod is as uniform as possible.
Devices of the type named above function exclusively for the filtration of media. In the process, a tempering, for example, cooling or heating, of the medium to be filtered, can be necessary for reasons of the filtration properties and/or the product treatment. According to the state of the art, special heat exchangers are provided for this purpose. Furthermore, it is known to equip filter membrane housings with a double sheath, in order to conduct a heating or cooling medium through the intermediate spaces.
In the process, it is desirable that especially large quantities of heat are exchanged in the entire membrane module. If the heat exchange operation is sufficient in the membrane module, then subsequently connected heat exchangers may be rendered unnecessary.
The purpose of the invention is to design a membrane module according to the generic concept of claim 1 in such a way that its heat exchanging capacity is increased relative to the aforementioned state of the art, and that in the process the equipment expense and the manufacturing costs arc kept as low as possible.
This purpose is achieved by the characteristics of claim 1. According to it, the individual ceramic rod is surrounded by a tube which is thus located in the annular gap between the outer surface of the ceramic rod and the sheath pipe. The tube is interrupted so that medium can flow through it from the inside to the outside or from the outside to the inside. The tube extends over a significant part of the length of the annular gap, and at best over its entire length. The tube can be made out of any metal, for example, out of plastic or out of steel. It can, for example, be constructed as a fabric, interwoven textile, or knit fabric. It can be made out of a perforated sheath.
The basic idea behind it is the following: The medium is conducted on its flowing path through the annular gap not only in the axial direction, but it is also forced into radial movements. In the process, it collides with the inner surface of the corresponding sheath pipe. In this way, the heat transfer between the medium and the sheath pipe is intensified, and to be precise, either in the sense of a heating or cooling of the medium, depending on the individual case.
A tube of this type can be inserted very easily into the module unit, but also just as easily removed, for example, for the purposes of cleaning. Functionally the individual tube is affixed onto the seal that is located between the one cap and the housing.